


Lumos

by cridecoeur



Series: Lumos [1]
Category: Harry Potter - J. K. Rowling, Sherlock (TV)
Genre: Alternate Universe - Fusion, Crack, M/M
Language: English
Status: Completed
Published: 2011-10-13
Updated: 2011-10-13
Packaged: 2017-10-24 13:50:35
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,239
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/264163
Author URL: https://archiveofourown.org/users/cridecoeur/pseuds/cridecoeur
Summary: <blockquote class="userstuff">
              <p>“Get up, John,” Sherlock says, in a tone that has John jerking upright in bed, immediately, and grappling for his gun in his bedside drawer, even as he says, “Sherlock, what is it?”</p><p>Incomprehensibly, Sherlock simply says, “Voldemort.”</p>
            </blockquote>





	Lumos

**Author's Note:**

> Otherwise known as "The One Where Sherlock Holmes Is Actually Regulus Black." I have... absolutely no way to defend this one, guys. I never even would have had the idea if I hadn't relistened to Bloc Party's "The Prayer" which always made me think of Regulus. This time it struck me as a very Sherlockian song and... things progressed from there - or regressed, I guess - into speculation about Sherlock's dressing gown, and how everyone around him is named ridiculous things, and the similarity of John's jumper-loving with the way Remus is always portrayed and also, seriously, Sherlock and Mycroft look nothing alike, but Sherlock and Sirius? Okay, yeah, this _entire thing_ is stretching. And don't even try to figure out the timeline. It's fucked. (Alright, technically, it just goes AU after Regulus steals the Horcrux, but other than that, it's pretty much nonsense.)

Sherlock wakes him at an ungodly hour of the morning - though Sherlock tends to forget there are such things ungodly hours of the morning being as how he tends to sleep only when exhaustion is so overwhelming he can’t possibly go on, going slack and soft-faced wherever he's sitting or laying or once, memorably, standing in the middle of a crime scene. He’s also shining a light directly into John’s eyes.

“Sherlock,” John groans, “what the hell.”

“Get up, John,” Sherlock says, in a tone that has John jerking upright in bed, immediately, and grappling for his gun in his bedside drawer, even as he says, “Sherlock, what is it?”

Incomprehensibly, Sherlock simply says, “Voldemort.”

“Is that - have you made another terrifying enemy?” John says, as he grasps his gun and levers himself out of bed. He squints against the light, bobbing at Sherlock’s fingertips, and realizes he’s holding… a twig. John blinks.

“Not made,” Sherlock says, “I’ve had him for years,” which doesn’t particularly narrow things down. “Come on,” Sherlock says, as he turns, holding the… what the hell is he doing with that twig, anyways? “I don’t have time to explain. We have to leave,” making for the stairs. John follows him, gun held at ready. This has become far too common an experience, since John has moved in with Sherlock, though, admittedly, Voldemort and the twig is new.

Downstairs is silent - of course it’s silent, it’s three in the bloody morning, but Sherlock moves as if he’s surrounded by enemies, already. John expects to be ambushed at any moment, but they make it downstairs and out the door safely.

“Sherlock, what about Mrs. Hudson?” John says.

“Already taken care of.” Sherlock says, and then, once more incomprehensible, adds that, “She went through the fireplace.”

“She went through the - Sherlock have you taken something?” John says.

Sherlock gives him a look that manages to be both scornful, condescending, and impatient at the same time. Sherlock has perfected that look. Sometimes, John imagines him practicing faces in the mirror to pull off just the right amount of haughtiness and superiority.

Before Sherlock has the chance to say whatever undoubtedly cutting thing John has just earned himself, there is a overwhelming roaring overhead and a - a bloody motorcycle comes flying out of the sky and lands on the street in front of 221b.

“Sherlock,” John says, very calmly, he thinks, for someone whose obviously been drugged and is hallucinating. “What did you slip me this time?”

“Don’t be ridiculous, John,” Sherlock says. “Anything I could give you would make your hallucinations far more incoherent.”

“Right,” John says. “Because Mrs. Hudson leaving through a fireplace and flying motorcycles obviously mean I’m coherent.”

“Quite,” Sherlock says, and John doesn’t even have the opportunity to start shouting before the man on the motorcycle takes off his helmet and John is shocked into silence by what looks like an older, more rugged version of Sherlock.

“Sherlock, what - “ John manages, before Sherlock cuts him off.

“John,” he says, with a twist to mouth John has come to associate with Mycroft and - no, really only Mycroft, “this is my brother, Sirius.”

“Sherlock,” John says, really quite concerned for one or both of their sanities, at this point, “Mycroft is your brother.”

Sherlock gives him a scornful look. “Don’t be ridiculous John,” he says. “We don’t even look alike.”

“Oi, Regulus,” the man - Sirius, if John’s apparently shattered psyche can be believed - says, “Get him on and let’s get out of here. I don’t fancy fighting a whole lot of Death Eaters on my own.”

“Don’t lie,” Sherlock says. “You’ve been looking for an excuse to do exactly that for years.”

“True,” Sirius says, with a cocksure sort of smile, “But Dumbledore’d be right pissed. And James’d hate to miss out on all the action.”

Sherlock looks very much as if someone just stuck a lemon in his mouth. “Don’t talk to me about him,” he says. Sirius snorts, and Sherlock gives him an impressive scowl before turning back to John. “Get on the bike, John,” he says.

“That thing flew out of the sky,” John feels the need to point out.

“It’s safer than Apparating,” Sherlock says, shifting about impatiently, in the way he has when John is failing to keep up, the way that means _come on, come on, hurry up_. “You might get splinched.”

“Right,” John says, “Of course,” and gets on the bike because, if he’s hallucinating all this, there’s probably no harm, and if he isn’t - never before meeting Sherlock would John have considered he was not hallucinating all this - then… well, that first terrifying tone of Sherlock’s is motivation enough.

“Right, then,” Sirius says, once John has swung himself onto the bike and Sherlock behind him - the bike is enormous, as if the proportions were taken from a giant. “Try not to fall off. I might not catch you.”

Sherlock shouts something, at that, but John can’t hear it over the sudden roar of the bike’s engine, as they tear down the street faster than can possibly be safe and then lift in the air in a way that… is actually sort of fantastic; it has nothing to do with getting shot at, but feels much the same, the same mad rush of adrenaline, almost heady. The wind snaps at them, colder the higher they rise, the stars bright overhead. When John looks down, he sees a sudden swarm of dark-robed figures on the street, appearing as if from thin air; overhead, green light blossoms, transforming, as it spreads, into a leering skull with a snake winding out from its mouth.

#

They touch down on an anonymous, though particularly grimy-looking London street, lined by townhouses that have most certainly seen better days. John gets off the bike, feeling half-way between exhausted and exhilarated. And… well, and really bloody confused, especially when Sirius takes a slip of paper from his pocket and hands it to him, saying, “Here, you won’t be able to get in without this.”

John looks down at the slip of paper. Written on in, in unnecessarily elaborate cursive, are the words _Number 12, Grimmauld Place_. “Where exactly do I need to get in - “ he says, before there’s a sound like very large things colliding, and another townhouse appears right in between two others, expanding out of nothing.

“You,” John says, turning to Sherlock, “are going to explain _so many things_.”

Sherlock gives him a look John can’t quite interpret - which isn’t all that unusual, since most of the things Sherlock does are incomprehensible to anybody who isn’t him, but he’s never even seen this particular look before.

“Get inside, John,” is all he says.

Sirius claps John on the back, suddenly, and he jerks and turns toward him in surprise, having half-forgotten he was there.

“Welcome to the world’s most carefully guarded hell-hole,” Sirius says. When John turns to look back at Sherlock, he looks… the sort of offended John’s used to seeing on people who have to deal with _Sherlock_ at his most condescending. He goes stalking off in the direction of… Number 12, Grimmauld Place, apparently, muttering undoubtedly poisonous things to himself.

“Right, then,” John says and follows him.

#

The first person John meets upon entering the house is Remus Lupin, who apparently also has an affinity for jumpers and scars of his own. John’s a little too busy thinking _why does everyone and everything involving Sherlock have such ridiculous names_ to notice much more than that.

“Muggle, eh,” he says, and John just stares at him a bit, then decides he probably doesn’t want to know what that means. Over Remus’ shoulder he can see Sirius and Sherlock circling each other, trading barbs. John has a strange moment of double vision where he sees Sherlock and Mycroft doing much the same before he shakes his head and resettles himself in the present.

“They really don’t get on,” he says, nodding at them.

Remus glances over his shoulder. “Regulus and Sirius?” he says, a strange smile crossing his face, mild and… something more subtle that John can’t quite untangle. “Oh, no. They trade off trying to kill each other and trying to save each other’s lives.” He shrugs. “Sibling rivalry. Regulus hates that Sirius managed to save his life, first.”

“Sherlock, you mean,” John says.

That same mild smile crosses Remus’ face. “Only to you.”

There is a sudden, resounding _crash_ and when they look back over at Sirius and… _Sherlock_ , John thinks firmly, Sherlock has his twig back out, a table has thrown itself violently against the wall, and Sirius is ducking and rolling at the same time he pulls out his own twig. Sherlock is shouting, “It wasn’t just _jewelry_ , and you know it!” and when Sirius regains his footing, he’s grinning like a maniac.

“Excuse me for a moment,” Remus says and then pulls out yet another twig, pointing it at Sherlock and Sirius and saying, very clearly, “ _Expelliarmus_!” and snatching both Sherlock and Sirius’ twigs out of the air as they fly out of their hands.

“Don’t make me come over there,” Remus says; Sherlock glares at him, poisonously, and Sirius says, “Oi, Moony, you’re no fun.”

“You’re not 16 anymore, Sirius,” Remus says, pointedly; Sirius starts scowling, and Sherlock stops scowling and looks as if he’s about to gloat - much the same as he does when he’s about to prove to an entire room of people what a genius he is - until Remus turns to him and says, “And your mother’s not here to be impressed, Regulus.”

Sirius laughs, outright, which is the point at which John learns Sherlock doesn’t actually need his twig to make things fly across the room.

#

“Don’t be dense, John,” Sherlock says, once John and Remus have managed to pull Sherlock and Sirius apart, and Sherlock has more or less explained himself, “I told you, it’s a wand, not a twig.”

“So,” John says, slowly, feeling as if his grip on reality has become very tenuous. “To recap. You’re a wizard who does magic with a twig,” Sherlock looks as if he’s about to protest, but John barrels on, “you almost got killed by zombies trying to steal jewelry, but your brother turned into a dog and saved you, and you ran away from a disappearing house to become a consulting detective because a lot of evil wizards want you dead.”

“It wasn’t just jewelry,” Sherlock mutters, as if that’s the most important part of what John just said.

“Sherlock!” John says.

Sherlock looks pained, but - “Essentially, yes,” he says. “Though you’ve missed several key points.”

“Oh, I’m sure I have,” John mutters and walks off.

#

Mrs. Hudson is not a witch, thankfully. Less positively - for John’s sanity, at least - she is _descended_ from them.

“Not a drop of magic in me, though,” she says, as she bustles around Grimmauld Place’s kitchen; in the corner, a particularly ugly little elf is glaring at her. “But, I’ve known Dumbledore for a long time. I met him when I was just a little girl. He thought it would be better for Sherlock to stay close to _someone_ from the wizarding world. And he helped with my husband, after all.” She turned towards him. “Tea, dear?”

“Please,” John says because Mrs. Hudson’s tea-making is one familiar thing in a world of _utter madness_.

#

That night, when John is lying in a foreign bed, in a foreign house, in a bloody foreign _world_ , Sherlock sweeps into the room with all the high drama he possesses - he has traded his coat for a set of robes in which he sweeps about, in a strikingly similar manner; John thinks the dressing gown makes a great deal more sense, now - and stands quivering at the edge of the bed, looking down at John.

“You’re angry,” Sherlock says, sounding almost tentative, in that way he has when he’s dealing with genuine human emotions, the one area in which John has ever seen him seem unsure of himself. Likely because he so seldom takes it upon himself to notice them and tries, at all costs, to pretend he doesn’t have any.

“Not really,” John says, honestly, because he isn’t, not anymore. “You could have picked a better way to tell me, though.”

“I didn’t tell you,” Sherlock says.

“No, I suppose not.” John says, “You kidnapped me in the middle of the night while dark wizards attacked our flat.”

Sherlock grimaces. “I said I was sorry about that.”

“I’m really not angry, Sherlock,” John says. Sherlock watches him for a moment before sitting on the bed beside him. He appears to be turning over something in his mind. He still looks the same, that hasn’t changed, and John can practically see the rapid-fire connections his mind is making as his face shifts, subtly.

“You know,” John says. “Regulus means ‘little king.’”

“As I am constantly reminded,” Sherlock says, but he looks down at John and cracks a smile. “Sirius means ‘flaming.’”

“Almost too easy,” John says, just to see Sherlock’s smile widen. “Come here, Sherlock.”

Sherlock pauses for a moment, before laying down beside John. They stare up at the ceiling for a moment, breathing quietly together.

“Sirius is also the brightest star in the sky,” Sherlock says.

“You cannot possible be competing with him over your _names_ ,” John says.

After too long of a pause, Sherlock says, “Of course, not,” and John sighs.

**Author's Note:**

> Okay, so, technically, Sirius means "scorcher" but you can't make nearly as many jokes out of that.


End file.
